Parallel Session 3.2: Geoengineering and the Arctic

Thursday, 09:00 - 10:30

04 I Seminarraum I/II

The Arctic is experiencing some of the most rapid climate change of anywhere in the world. Offsetting these changes has been the explicit target of multiple geoengineering proposals. The potential effects of climate change and geoengineering would impact the people and natural resources of this sensitive region and would have knock-on effects for numerous areas throughout the rest of the world.
In this session, we explore the broad scope of geoengineering and the Arctic. We welcome proposals in a wide variety of areas, including technologies that are designed to be deployed in or directly impact the Arctic, natural and social science research on the effects and impacts of geoengineering on the Arctic, and the geopolitical role of the Arctic. Submissions relating to SRM, CDR, or any other category of geoengineering are welcome.

Talks:

Holly Jean Buck

Co-producing knowledge about albedo modification in the Arctic Albedo modification could cool the planet globally, or regionally in the Arctic, bringing risks, possible benefits, and political complexity. Different designs of climate intervention can produce different climatic results, and hence have different impacts on communities. This is one of many reasons why the co-production of knowledge about them is crucial. Having local people evaluate potential impacts to their communities, in terms of their own priorities and concerns, generates knowledge about how geoengineering can affect vulnerability and resilience to climate change on community and regional scales. Here, we present an example of a project which incorporates citizen ideas, concerns, and questions early into the research of albedo modification in the Arctic, with the rationale that “upstream public engagement” is better for science and society. For this purpose, we conducted semi-structured interviews, public lectures and focus groups in Finnish Lapland, by and above the Arctic Circle, about climate intervention, and climate modeling work based upon this qualitative work to examine scenarios of winter duration and conditions under climate change and climate engineering. We returned a year later to share these scenarios and explore how thoughts about climate engineering changed over time. In this talk, we discuss the tension between different boundings of the problem under investigation in projects of knowledge co-production, and how to use that tension productively.

David Mitchell

Cirrus Cloud Thinning or CCT, if feasible, should be most effective at high latitudes. Recent global climate modeling (GCM) research shows that seeding cirrus clouds in only one hemisphere at a time, at mid-to-high latitudes during the half-year when the zenith-sun is relatively low, may produce about the same amount of globally averaged surface cooling as produced by seeding the entire planet. But this assumes that cirrus clouds over this region and during this period are largely formed through homogeneous freezing nucleation (henceforth hom).
To determine whether these conditions exist in nature, a new satellite remote sensing method was developed that retrieves the ice particle number concentration, Ni, from optically thick cirrus clouds. Knowing Ni, conservative estimates of the cirrus fraction formed through hom can be made. This is because only hom can account for Ni exceeding ~ 250 liter-1 in regions typically having relatively low concentrations of ice nuclei. It was surprising to discover that the above conditions required for CCT do apparently occur in nature. GCM simulations based on these cirrus cloud retrievals indicate that CCT has a cooling potential of ~ 2 W m-2 in the S. Hemisphere and ~ 1.3 W m-2 in the N. Hemisphere.

Ulrike Lohmann

We investigate a climate engineering method aims at cooling the climate by modifying cirrus clouds. On average, cirrus clouds have a net warming effect on climate by absorbing and emitting longwave radiation back to earth that outweighs their cooling effect by scattering solar radiation. The climate engineering approach is to reduce the lifetime of cirrus clouds and change their optical properties so that more longwave radiation can escape into space. This could be done by “seeding” the atmosphere with very efficient ice nuclei which would prevent the formation of “homogeneous cirrus clouds”, a type of cirrus cloud that has the strongest warming effect.
To study the effectiveness of cirrus seeding we use the global climate model ECHAM-HAM which simulates the microphysics of clouds in detail. We find that the effectiveness of seeding strongly depends on the model setup and the simulated processes. This makes the investigation of this climate engineering method very challenging, and there is no final judgement yet, whether cirrus seeding could effectively cool the climate or not. We also investigate limited cirrus seeding in the Arctic winter where their longwave effect should be largest.

Hilairy E. Hartnett

As the Earth’s climate has changed, Arctic sea ice extent has decreased drastically. It is likely that the late-summer Arctic will be ice-free as soon as the 2030s. This loss of sea ice represents one of the most severe positive feedbacks in the climate system, as sunlight that would otherwise be reflected by sea ice is absorbed by open ocean. In our opinion, it is unlikely that CO2 levels and mean temperatures can be decreased in time to prevent this loss of Arctic sea ice, which may result in irreversible disruption of Arctic communities and ecosystems.
Here we investigate a means for enhancing Arctic sea ice production by using wind power during the Arctic winter to pump water to the surface, where it will freeze more rapidly. We show that where appropriate devices are employed, it may be possible to increase ice thickness above natural levels, by about 1 meter over the course of the winter. We examine the effects this has in the Arctic climate, concluding that deployment over 10% of the Arctic, especially where ice survival is marginal, could more than reverse current trends of ice loss in the Arctic, potentially arresting the ice-albedo feedback.

Helene Muri

A changing climate in the High North and the Arctic widely affects states, international organizations and private interests, including emerging economies in Asia. Indigenous people, fishing and ecosystems, oil and gas politics, and sea transportation are all impacted by the climate of the High North. Here we address how the Arctic climate would respond to radiation management climate engineering using an Earth system model. The experiment targets to offset the anthropogenic radiative forcing difference between the high CO2 concentration scenario RCP8.5 and the middle of the road scenario RCP4.5. The forcing is offset by individually deploying stratospheric aerosol injections (SAI), marine cloud brightening (MCB) and cirrus cloud thinning (CCT). Some notable differences in the climate response in the High North are seen. Including: MCB and SAI see warmer continents across Eurasia and North America compared to RCP4.5 considering reduced cooling efficiency during the polar night. The hydrological cycle is enhanced over Eurasia from CCT with its enhanced latent heat flux. And furthermore important differences in the sea ice cover is found. The Arctic navigation potential increases substantially in all cases, with possibility for new shipping routes along the Northwest Passage and new optimal routes more northwards of the Russian coast.

Sergey Kostrykin

The geoengineering effect of sulfur dioxide injection into the lower stratosphere (as a precursor of sulfate aerosols) on the Arctic climate system is considered. It is supposed to use sulfur compounds currently emitting into the surface atmospheric layer by "JSC NorNickel" enterprise. The global model of the earth climate system INMCM3 is used for the computation. The calculations are based on the assumption that concentrations of greenhouse gases (CO2 , CH4 и N2O) will increase in accordance with IPCC scenario RCP8.5 until the middle of this century. Calculations have shown that injection of 1.9 Mt SO 2 /year into the lower stratosphere could slow down significantly the Arctic warming and reduce risk of total dissolution of the Arctic Ocean multiyear ice cover. In addition, the use of SO2 emitted by "JSC NorNickel" enterprise as a precursor of stratospheric sulfate aerosols would decrease extremely high atmospheric pollution level in Norilsk.

Albedo modification could cool the planet globally, or regionally in the Arctic, bringing risks, possible benefits, and political complexity. Different designs of climate intervention can produce different climatic results, and hence have different impacts on communities. This is one of many reasons why the co-production of knowledge about them is crucial. Having local people evaluate potential impacts to their communities, in terms of their own priorities and concerns, generates knowledge about how geoengineering can affect vulnerability and resilience to climate change on community and regional scales. Here, we present an example of a project which incorporates citizen ideas, concerns, and questions early into the research of albedo modification in the Arctic, with the rationale that “upstream public engagement” is better for science and society. For this purpose, we conducted semi-structured interviews, public lectures and focus groups in Finnish Lapland, by and above the Arctic Circle, about climate intervention, and climate modeling work based upon this qualitative work to examine scenarios of winter duration and conditions under climate change and climate engineering. We returned a year later to share these scenarios and explore how thoughts about climate engineering changed over time. In this talk, we discuss the tension between different boundings of the problem under investigation in projects of knowledge co-production, and how to use that tension productively.

Ben Kravitz is an expert in climate modeling studies of solar geoengineering. He is the co-founder and coordinator of the Geoengineering Model Intercomparison Project (GeoMIP), a collaboration between climate modeling centers throughout the world to better understand the expected climate effects of various geoengineering scenarios. Results from GeoMIP are featured in the Fifth and Sixth IPCC assessment reports, for which Ben serves as a contributing author, the 2015 National Research Council reports on climate intervention, and recent testimony to Congress. Ben is an assistant professor at Indiana University in the Department of Earth and Atmospheric Sciences, and he maintains a joint appointment in the Atmospheric Sciences and Global Change Division at Pacific Northwest National Laboratory. In addition to coordinating and participating in GeoMIP, his current activities include using engineering and mathematical techniques in climate models to better understand climate feedbacks, studying teleconnections in high latitude climate, and developing climate model emulators for use in Integrated Assessment Models.

Douglas MacMartin splits his time between Mechanical & Aerospace Engineering at Cornell University, and Computing + Mathematical Sciences at the California Institute of Technology. His research lies at the intersection between engineering feedback analysis and climate dynamics, with a primary focus on solar geoengineering – working to develop the knowledge base for society to make informed decisions. In addition to applying engineering analysis to climate dynamics, he is also involved in control design for the Thirty Meter Telescope. He received his Bachelors’ degree from the University of Toronto in 1987, and Ph.D. in Aeronautics and Astronautics from MIT in 1992; prior to joining Caltech in 2000, he led the active control research and development program at United Technologies Research Center.

Ulrike Lohmann is Professor at the Institute for Atmospheric and Climate Science at the ETH Zurich. Her research focusses on the role of aerosol particles and clouds in the climate system combining laboratory work and climate model simulation techniques.
Lohmann received her PhD in Meteorology in 1996 from the Max Planck Institute for Meteorology in Hamburg. In the following years, she was Postdoctoral fellow at the Canadian Centre for Climate Modelling and Analysis in Victoria and associate Professor in Atmospheric Science at the Canadian Dalhousie University, Halifax.

Dr. David Mitchell has contributed to the peer-reviewed literature in the atmospheric science sub-disciplines of cloud physics, radiation, remote sensing and climate dynamics (North American monsoon). He published the first paper on the radiation management method known as “cirrus cloud thinning” (CCT) and has developed a satellite remote sensing method to test the viability of CCT and to verify its impact should it ever be tested in a field campaign. He has given 40 invited talks at universities and research institutes in the USA, the U.K., Germany, Mexico, Norway, France, and Sweden.

Holly Jean Buck is a postdoctoral fellow at UCLA's Institute of the Environment and Sustainability. Her research interests include agroecology and climate-smart agriculture, energy landscapes, land use change, new media, and science and technology studies. She has written on several aspects of climate engineering, including humanitarian and development approaches to geoengineering, gender considerations, and the social implications of scaling up negative emissions. Her book After Geoengineering: Climate Tragedy, Repair, and Restoration (Verso Books, 2019) looks at best-case scenarios for carbon removal and solar geoengineering. She holds a doctorate in Development Sociology from Cornell University, and lives in Los Angeles, California.

Rafe Pomerance is Chairman of Arctic 21, a network of organizations focused on communicating issues of Arctic climate change to policy makers and the general public. Arctic 21, which operates under the auspices of WHRC, seeks to establish a framework for Arctic policy based on the question, “what is the Arctic we have to have?” Rafe is a member of the Polar Research Board of the National Academy of Sciences and an independent climate strategies consultant. Rafe has spent much of his career on global warming including his work with Friends of the Earth where he served as President from 1980 to 1984, the World Resources Institute as a senior associate for climate change and ozone depletion policy and as a Deputy Assistant Secretary of State for Environment and Development (1993-99) and climate negotiator and as President of the Climate Policy Center (CPC). Rafe was a founder and Chairman of the Board of American Rivers, Chairman of the Board of the League of Conservation Voters and of the Potomac Conservancy.

Hilairy Hartnett is a biogeochemist, jointly appointed in the School of Earth and Space Exploration and the School of Molecular Sciences at Arizona State University. She is co-director of the ASU PlanetWorks Initiative and a Senior Sustainability Scientist in ASU’s Global Institute of Sustainability. Her research interests range from Astrobiology to Urban Ecology; most recently she is developing technologies for Arctic Ice Management and building capacity for transdisciplinary conversations around planetary management. As an oceanographer and organic geochemist her basic research focuses on carbon and nitrogen cycling, she applies field- and laboratory-based techniques to investigate the processes and feedbacks that promote and/or limit the transfer of elements (C, N, and P) and energy between different geological pools; including living and non-living organic matter. Her studies utilize investigations of reaction mechanisms that operate on time scales from days to millennia. She received a bachelor’s degree in chemistry from Vassar College in 1990, a PhD in Oceanography from the University of Washington 1998.

Helene Muri is a researcher at the University of Oslo’s Meteorology and Oceanography Section. Current work is focused on Earth system modelling of various climate geoengineering techniques including BECCS, SRM and cirrus cloud thinning, and actively participates in GeoMIP (Geoengineering Model Intercomparison Project) and CDR-MIP. Furthermore, she contributed towards the EuTRACE climate geoengineering assessment report. Previously, she held an ERC Advanced grant post-doc at Université catholique de Louvain working on climate model - data comparisons for paleo-climate studies. She gained her D.Phil degree from the University of Oxford’s Atmospheric Oceanic and Planetary Physics department in 2009 on the topic of forcing evaluation in climate model ensembles, as part of the climateprediction.net project.

Ilona Mettiäinen works as a researcher at the Arctic Centre of the University of Lapland in Rovaniemi, Finland. In her doctoral research, she studies strategic adaptation to climate change, particularly the use and co-production of knowledge for planned, proactive responses to climate change on the subnational level. Her other fields of expertise include Arctic human geography, sustainable Arctic tourism, and collaborative planning methods. Mettiäinen’s current research projects include Blue-Action (Horizon2020) case study on developing climate services for winter tourism business in Northern Finland, and “Albedo modification in the Arctic” together with Cornell University. Her traveling science communications photo exhibition “Nanoq – Imag(in)ing climate change” has been invited to seven venues in 2016-2017 in Finland and in the USA.